Military searchlight



E. A. SPERRY.

MILITARY SEARCHUGHT.

APPLICATION FILI-:D MAY25; 1916.

Patented Apr. M, 1922 2 SHEETS-SHEET l.

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` E.. A. SPERRY. MILITARY SEARCHLIGHT.

APPLICATION FILED MAY 25, 19181 Patented Apr. IIL-1922.

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m. y. W ,N WY/ M Nmn :WWA m .H m/ W Ly B PATENT @FFHQO ELIHER A. SPERRY,F BROOKLYN, NEW YORK.

MILITARY SEARCHLIGHT.

Specification of Letters Patent.

Application filed. May l25, 1916. Serial No. 99,715.

To all whom t mag/concern:

Be it known that I, ELMER A. SPERRY, a citizen of the United States ofAmerica, residing at borough of Brooklyn, New York city, in the countyof Kings and State of New York, have invented certain new and usefulImprovements in Military Searchlights, of which the following is aspecification. 'Y

This invention relates to they art of illuminating battlefields. Modernwarfare has developed the range and accuracy of guns to such an extentthat it has been found impossible to employ searchlights in connectionwith trench warfare on the European battlefields, since almost as soon'as the light was turned on, it would be shot to pieces by the enemysgun fire.

'Ihe object of this invention is to devise a searchlight adapted for usein connection with any form of land fortication's, such as trenches,inland forts or coast defense fortifications.

. tom of the ost, thesection being taken on line lL-4, tion of the same.tion of a modified mirror.

ig. 5. .Fig is a side eleva- Fig. 6 is a rear eleva- Fig. 7 is a sideelevation of the same. Fig. 8 is a. sectional view of the searchlight,the sectionl being taken on line 8 8, Fig. 10. Fig. 9 is an enlargedplan view of` the pan used to prevent hot particles of carbon fromfalling on the mirror. Fig. 10 is a section on line 10-10, Fig. 2. Fig.11l is detail of the scale on the elevating mechanism.

AAccording to my invention, I design the lights so that the searchlightitself 1 may be placed entirely below the ground in a sheltered pit 2 orbehind a parapet or the like. The searchlight is mounted in a normallyvertical position, so `that the beam is projected vertically upward.Positioned above the lamp on a post or mast 3 is a re- Hector or mirror-4t, preferably inclined at .about to the vert-ical, so that the relectedbeam will be. approximately horiJ zontal. The mast is preferably made ofa plurality of sections 64 and 65 so that it may be readilydisassembled.

'I he mlrror may be made of the usual material or it may be made ofpolished metal, so as not to be damaged to any great eX- tent by smallbullets and fragments of shells.

In order to effect changes in the elevation of the beam, both thesearchlight and mast are mounted on horizontal trunnions 6, 7 inbrackets 8. 9, the mast being rigidly clamped to Ithe drum by means ofone or more brackets 10. Preferably the drum is placed on the` oppositeside of the 4pivots from the major portion of the mast and the mirror soas to counterbalance the structure. The bracket 11 which supportstrunnion 7 is provided with a large segmental gear 12 with which thepinion 13 on stud shaft 14 meshes. This gearing is rotated from handle15 by means of a pinion 17 on the shaft of said `handle and the gear 18on said stud shaft 14. The segmental gear 12 is preferably provided withindications 16 so that the operator may know the elevation of the beam.rFhe scale is graduated in each direction from the vertical or zeroposition. Preferably additional, comple. mentary graduations 60 areprovided, (see Fig. 11) fora purpose hereinafter explained.` Thereference pointer 61 for this scale, as well as the pointer 62 for thescale 63 on )Patented Apr.. 1111, 1922.-

the rotatable base 20 ispreferably made I adjustable so that any errorsmade in the positioning of the mirror at the proper angle can readily becompensated for by moving the reference indices. Both scales arepreferably divided, or made in twoj parts which read from zero in bothdirec?A tions. This is especially important on scale 63, since Vitenables the operator to obtain like readings on both sides of the base.

The two brackets 8 and 9 are mounted;

oh a base 20, rotatable in azimuth, whereby the entire searchlight maybe revolved in the usual'manner.- I also prefer to Provide means wherebythe beam may be thrown directly upward from the searchlight withoutrotatably mounted on the top small rod 22 extending axially through saidpost serves to rotate the mirror from its posit-ionlin the beajm to aposition without the beam (see dotted lines, Fig. 2). At its lower endrod 22 is provided with a handle 23 by means of which the mirror isrotated. A snap button 24 may also be secured to the rod to lock themirror in the desired position eitherwithin or without the beam byengaging depressionsy 124 or 125 in the bottom of foot 128. The post ispreferably made adjustable so that the'entire mirror can be lowered tothe ground for inspection or renewal. For this purpose the 'two clamps25 and 26 by means of which the post is secured to bracket 11, arehinged at 26 and 27 respectively, so as to swing outwardly and releasethe post, wing nuts 27 being provided to hold the clamps in place. Uponrelease of the clamps the entire post may be revolved upon the foot 128.Release of the clamps also permits rotation of the post on its` own axisfor the purpose of adjustment.

Noy attempt has been made to disclose a complete searchlight mechanismas I may use in my lamp any 'form of light source adapted to work in avertical position. I prefer, however, to employ the type of lightdisclosed in my copending application for improvements in searchlights,Serial No. 21,661, filed April`16th, 1915. This type of light not onlygives a very much greater beam candlepower than any other, but also isadapted to work inany position, horizontal vertical or inclined. In Fig.8 the positivelholder is'shown at 30, and the negative holder 'at 31.

In order to prevent .the hot particles of carbon', copper or othermaterial from dropof post 3. A

l ping onto the polished surface of the mirror -In other words when fromthe electrodes and electrode holders I prefer to'employ 'a shield or pan32 which may be' kept below the arc by being pivotally supported so asto hang in a vertical position'irrespective of the position vof thedrum. Preferably this pan is of openwork metal such as fine wire gauze,preferably of open mesh soA that la minimum amount of light may be shutofi thereby. Mica or 'similar transparent material may also be used. In.the embodiment shown the pan is suspended from small pivoted arms 33,,34. These arms'normally rest against pins 35 in the side o f the drum,but when lthe drum @is tilted to more than a Vthe arms revolve on thepivots and permit the. pan to drop without the zone of light`predetermined angle from the mirror (see dotted lines in Fig. 10). thedrum is tilted through such an angle. that the hot particles would notstrike the mirror the pan is removed preferably automatically from infront of the mirror to the dark space bemy searchlight in this position,there is provided an exhaust fan 38 mounted in a housing 38 on one sideof the drum. The inlet openings 39 and 40 in one side of the searchlightare so arranged that a circulating current of air will pass'over thefront window 40 and will sweep over the surface of the projector 41without causing flickering of the light. For this purpose, suitableguiding shields 42 and 43 may be provided. The drafts of air thuscreated not only keep the reflector and front door cool but serve towashthem clean -of smoky deposits and particles which otherwise wouldseriously lessen the efficiency of the lamp after a few hours run.

A modified form of` mirror mounting is shown in Figs. 6 and 7. Accordingto this form of the invention the elevation of the beam is adjusted bytilting the mirror 4 on the post 3 by means ofa chain 4 5 or other meansreadily accessible from below the mirror. In this form of the inventionalsov it is unnecessary to provide means to rotate the mirror withoutthe beam since very little shadow will be caused by the mirror if it isy tu lned into a position parallel with post3, as shown in Fig. .7.

One important use of the invention will be illustrated by supposing thatthe searchliglit'when in the position shown in Figsll and 2 picks up ahostile aeroplane approach-` ing in the distance. *As the aeroplanecomes nearer and climbs higher and higher in the zenith, the searchlightis tilted'backwardly by means of handle 15'until it is ltilted throu' han angle of say 45. The mirror may t en be quickly removed from the beamof light by turning handle 23, and the` searchlight quickly andaccurately brought to bear upon the aeroplane directly byrotating ortilting the searchlight in the opposite direction. fTheoperator can thuskeep the searchlight directly upon thel machine until it again dropsbelow a predetermined position when the mirrorl can be again broughtinto play and the searchlight again quickly tilted.

By securing the m'ast to the searchlight and oscillating or turning.them together,

another important advantage is secured over the usual searchlight. Thisis dueto the fact Lamps? .other means. Also, while it is designed to usethe various features and elements in the combination and relationsdescribed, some of these may be altered and others omitted without`-interfering with the more general results outlined, and the inventionextends to such use.

Havingydescribed my invention, what l claim and desire to secure byLetters 4Patent 1. A. military searchlight comprising a drum supportedon asubstantially horizontal aXis in a normally vertical position, areflector, means Vfor supporting said reflector aloft journalled foroscillation about said horizontal axis, means whereby the drum andsupporting means may be rotated about said axisand a scale forindicating the elevation, said scale being provided with major andcomplementary angular graduations.

2. rThe combination with a normally vertical searchlight,of a mastmounted adjacent said light, a reflector supported on' said mast, andmeans whereby said reflector may be moved within and without thesearchlight beam.

3. The combination withl a normally vertical searchlight, of a mastmounted adjacent said light, a reflector swivelled about a normallyvertical axis on said mast, and means whereby said reHector may be movedwithin and without the searchlight beam.

4f. A military searchlight comprising a ro- .'tatably mounted base, asearchlight supported in a normally vertical` position on said base, areflector slupported above said searchlight and means whereby saidreflector may be placed within or without the beam.

5. rlhe combination with a normally very tical searchlight, of a mastmounted adjacent said light, a rellector supported on said mast,

a shaft extending parallel said mast and provided with manipulatingmeans, said shaftbeing secured to said re-lector vvadjacent its topwherebythe reector maybe turned without the beam. v

6. The combination with a normally vertical searchlight, of a hollowmast 'mounted adjacent said light,'a reflector supported on vsaid mast,Aa shaft extending through said mast and provided withmanipulatingmeans,

said shaft being secured to said reflector adjacent its top whereby thereflector may be turned without the beam.4

7. 'llhe combination with a searchlight mounted so that it may asssume avertical position including a projector and a source of light, ofaperforated or openwork catch pan pivotally supported between. the saidlight source and the projector to protect the latter.

8. The combination with a searchlight piv- `otally mounted yso that itmay assume a vertical position including a projector and asource oflight, of a catch `pan pivotally suspended between the said light sourceand the projector to protect the latter, the pivotal axis of support forsaid pan being approximately in horizontal alignment with the saidsource.

9. The combination with a searchlight pivotally mounted so that it mayassume a normally vertical position including a drum, a projector and asource of light, of a catch pan suspended from opposite points adjacentthe drum between the said light source and the projector to protect thelatter.

10. rl`he combination with a searchlight drum and projector suspendedfor oscillation about a horizontal axis, of an arm pivoted in the sideof the drum, a catch pan suspended from adjacent the free end' of saidarm, a stop for supporting said arm in an inclined upstanding position,whereby said arm will revolve and drop the pan when the searchlight isturned through a predetermined angle.

11. The combination with a searchlight pivotally mounted in a normallyvertical position including a projector and a source of light, of acatch pan suspended between the said light source and the projector toprotect the mirror, and means for removing said pan to a point withoutthe beam when the searchlight is turned through a predetermined angle. l

12. A searchlight comprising a source oi light, a projector, a shieldsuspended between said source and 'projector when a ver- 105 tical linethrough said source intersects said projector, and means for causingsaid pan to move out of the path of the light rays passing from saidsource to said projector as soon as the above mentioned vertical line isbeyond the edge of the latter.

13. ln combination, a normally vertical searchlight oscillatable about ahorizontal axis, a reflector mounted above said searchlight, meansconnecting said searchlight and reflector for maintaining the latter inthe beam of the searchlight and means controlled from 'a point adjacentsaid searchlight for removing said reflector from said beam.

14. In a searchlight including a projector and a source of light, acatch pan within said searchlight and means whereby said catch pan maybe placed in its inoperative position without the path of the light beamand in its operative positive position `to shield the projector inresponse to changes in the position of the searchlight.

15. ln a searchlight including a projector and a source of light, aprojector shield loagar miens? projector, and means responsive to theposiporting the bottom yof the mast, and detachtion of the searchlightfor removing said able clamping means for securing said mast shield fromits operative position to a posito said foot and searchlight, and amirror 10 tion Without the light beam. secured adjacent the top of saidmast.

5 16. 'The combination of a searchlight -hav- In testimony whereof Ihave aiixed my ing a drum and supported for oscillation, on signature.horizontal pivots, of a mast, a foot for sup- ELMER A. SPERRY.

